Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Old Irish ed
← Irish feá (link)
← Proto-Indo-European *ís (inherited)
← Latin id (cognate)

→ Irish ea (inherited)
→ Irish feadh (inherited)
→ Irish eadh (inherited(ga/gd))
→ Irish feá (inherited)
→ Scottish Gaelic feadh (inherited)